U.S. patent application number 11/054918 was filed with the patent office on 2006-08-10 for devices and methods for the delivery of molecular sieve materials for the formation of blood clots.
This patent application is currently assigned to Z-Medica, LLC. Invention is credited to Jeffrey Horn, Raymond Huey.
Application Number | 20060178609 11/054918 |
Document ID | / |
Family ID | 36570531 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060178609 |
Kind Code |
A1 |
Horn; Jeffrey ; et
al. |
August 10, 2006 |
Devices and methods for the delivery of molecular sieve materials
for the formation of blood clots
Abstract
An apparatus for promoting the clotting of blood and controlling
bleeding comprises a receptacle for retaining molecular sieve
material in particulate form therein. A pad for controlling
bleeding comprises a mesh structure and a rigid or semi-rigid
support attached to the mesh structure to facilitate the
application of pressure to the pad and the wound. A bandage
applicable to a bleeding wound comprises a mesh structure and a
flexible substrate attached to the mesh structure, the substrate
being a cloth or plastic member that may be adhesively attached to
cover a wound. In any embodiment, at least a portion of the
receptacle or mesh structure is defined by a mesh having openings
therein, and at least a portion of the particulate molecular sieve
material is in direct contact with blood.
Inventors: |
Horn; Jeffrey; (Rocky Hill,
CT) ; Huey; Raymond; (Orange, CT) |
Correspondence
Address: |
MICHAUD-DUFFY GROUP LLP
306 INDUSTRIAL PARK ROAD
SUITE 206
MIDDLETOWN
CT
06457
US
|
Assignee: |
Z-Medica, LLC
Wallingford
CT
|
Family ID: |
36570531 |
Appl. No.: |
11/054918 |
Filed: |
February 9, 2005 |
Current U.S.
Class: |
602/48 |
Current CPC
Class: |
A61L 15/42 20130101;
A61L 15/18 20130101 |
Class at
Publication: |
602/048 |
International
Class: |
A61F 13/00 20060101
A61F013/00 |
Claims
1. An apparatus for promoting the clotting of blood, comprising: a
receptacle for retaining molecular sieve material in particulate
form therein, at least a portion of said receptacle being defined
by a mesh having openings therein; wherein when treating a bleeding
wound, application of said apparatus causes at least a portion of
said particulate molecular sieve material to come into contact with
blood through said openings.
2. The apparatus for promoting the clotting of blood of claim 1,
wherein said molecular sieve material is a zeolite.
3. The apparatus for promoting the clotting of blood of claim 2,
wherein said zeolite comprises particles having diameters of about
0.2 mm to about 10 mm.
4. The apparatus for promoting the clotting of blood of claim 2,
wherein said zeolite comprises particles having diameters of about
1 mm to about 7 mm.
5. The apparatus for promoting the clotting of blood of claim 2,
wherein said zeolite comprises particles having diameters of about
2 mm to about 5 mm.
6. The apparatus for promoting the clotting of blood of claim 1,
wherein said mesh structure is flexible.
7. The apparatus for promoting the clotting of blood of claim 1,
wherein at least one particle of said particulate molecular sieve
material protrudes through one of said openings.
8. A pad for controlling bleeding, said pad comprising: a mesh
structure; particles of molecular sieve material retained in said
mesh structure; and a support attached to said mesh structure;
wherein said mesh structure is defined by openings sized to
accommodate the flow of blood therethrough.
9. The pad of claim 8, wherein said molecular sieve material is a
zeolite.
10. The pad of claim 9, wherein said zeolite comprises particles
having diameters of about 0.2 mm to about 10 mm.
11. The pad of claim 9, wherein said zeolite comprises particles
having diameters of about 1 mm to about 7 mm.
12. The pad of claim 9, wherein said zeolite comprises particles
having diameters of about 2 mm to about 5 mm.
13. The pad of claim 8 wherein said support is configured to have a
pressure applied thereto to enable said pad to be retained on a
bleeding wound.
14. A bandage applicable to a bleeding wound, said bandage
comprising: a substrate; a mesh mounted on said substrate; and
particles of a molecular sieve material retained in said mesh; said
mesh defined by a plurality of members arranged to define openings,
said openings being dimensioned to accommodate the flow of blood
therethrough.
15. The bandage of claim 14, further comprising an adhesive on said
substrate, said adhesive being configured to facilitate the
retaining of said bandage on the skin of a wearer.
16. The bandage of claim 14, wherein said substrate includes
holes.
17. The bandage of claim 14, wherein said molecular sieve material
is a zeolite.
18. A method of dressing a bleeding wound, said method comprising
the steps of: providing a molecular sieve material in particle form
and retained in a mesh structure; placing said mesh structure on a
bleeding wound such that said molecular sieve material contacts
wounded tissue of said bleeding wound; applying pressure to said
mesh structure; and removing said mesh structure from said
wound.
19. The method of claim 18, further comprising the step of holding
said mesh structure on said bleeding wound using a strapping
device.
Description
TECHNICAL FIELD
[0001] The present invention relates generally to blood clotting
devices and, more particularly, to blood clotting materials,
devices incorporating such materials, and methods for the delivery
of such materials for use as bleeding control devices.
BACKGROUND OF THE INVENTION
[0002] Blood is a liquid tissue that includes red cells, white
cells, corpuscles, and platelets dispersed in a liquid phase. The
liquid phase is plasma, which includes acids, lipids, solublized
electrolytes, and proteins. The proteins are suspended in the
liquid phase and can be separated out of the liquid phase by any of
a variety of methods such as filtration, centrifugation,
electrophoresis, and immunochemical techniques. One particular
protein suspended in the liquid phase is fibrinogen. When bleeding
occurs, the fibrinogen reacts with water and thrombin (an enzyme)
to form fibrin, which is insoluble in blood and polymerizes to form
clots.
[0003] In a wide variety of circumstances, animals, including
humans, can be wounded. Often bleeding is associated with such
wounds. In some circumstances, the wound and the bleeding are
minor, and normal blood clotting functions in addition to the
application of simple first aid are all that is required.
Unfortunately, however, in other circumstances substantial bleeding
can occur. These situations usually require specialized equipment
and materials as well as personnel trained to administer
appropriate aid. If such aid is not readily available, excessive
blood loss can occur. When bleeding is severe, sometimes the
immediate availability of equipment and trained personnel is still
insufficient to stanch the flow of blood in a timely manner.
[0004] Moreover, severe wounds can often be inflicted in remote
areas or in situations, such as on a battlefield, where adequate
medical assistance is not immediately available. In these
instances, it is important to stop bleeding, even in less severe
wounds, long enough to allow the injured person or animal to
receive medical attention.
[0005] In an effort to address the above-described problems,
materials have been developed for controlling excessive bleeding in
situations where conventional aid is unavailable or less than
optimally effective. Although these materials have been shown to be
somewhat successful, they are sometimes not effective enough for
traumatic wounds and tend to be expensive. Furthermore, these
materials are sometimes ineffective in some situations and can be
difficult to apply as well as remove from a wound.
[0006] Additionally, or alternatively, the previously developed
materials can produce undesirable side effects. For example, prior
art blood clotting material is generally a powder or a fine
particulate in which the surface area of the material often
produces an exothermic reaction upon the application of the
material to blood. Oftentimes excess material is unnecessarily
poured onto a wound, which can exacerbate the exothermic effects.
Depending upon the specific attributes of the material, the
resulting exothermia may be sufficient to cause discomfort to or
even burn the patient. Although some prior art patents specifically
recite the resulting exothermia as being a desirable feature that
can provide clotting effects to the wound that are similar to
cauterization, there exists the possibility that the tissue at and
around the wound site may be undesirably impacted.
[0007] Furthermore, to remove such materials from wounds,
irrigation of the wound is often required. If an amount of material
is administered that causes discomfort or burning, the wound may
require immediate flushing. In instances where a wounded person or
animal has not yet been transported to a facility capable of
providing the needed irrigation, undesirable effects or
over-treatment of the wound may result.
[0008] Bleeding can also be a problem during surgical procedures.
Apart from suturing or stapling an incision or internally bleeding
area, bleeding is often controlled using a sponge or other material
used to exert pressure against the bleed site and/or absorb the
blood. However, when the bleeding becomes excessive, these measures
may not be sufficient to stop the flow of blood. Moreover, any
highly exothermic bleed-control material may damage the tissue
surrounding the bleed site and may not be configured for easy
removal after use.
[0009] Based on the foregoing, it is a general object of the
present invention to provide devices for controlling bleeding and
methods of their use that overcome or improve upon the prior
art.
SUMMARY OF THE INVENTION
[0010] According to one aspect, the present invention resides in an
apparatus for promoting the clotting of blood, thereby controlling
bleeding. The apparatus comprises a receptacle for retaining
molecular sieve material in particulate form therein. At least a
portion of the receptacle is defined by a mesh having openings
therein such that when the apparatus is applied to a bleed site,
the particulate molecular sieve material comes into contact with
blood through the openings.
[0011] Other aspects of the present invention include a pad for
controlling bleeding and a bandage applicable to a bleeding wound.
In both the pad and the bandage, there is a mesh structure and
particles of molecular sieve material retained therein. In the pad
embodiment, there is a rigid or semi-rigid support attached to the
mesh structure to facilitate the application of pressure to the pad
and the wound. In the bandage, there is a flexible substrate
attached to the mesh structure, the substrate being a cloth or
plastic member that may be adhesively attached to cover a wound. In
any embodiment, the mesh structure may be defined by a plurality of
members (strands, filaments, or strips of synthetic or natural
material) interconnected and arranged to define openings. The
openings are sized to allow contact to be maintained between the
particles of the molecular sieve material and blood.
[0012] In yet another aspect of the present invention, a method of
dressing a bleeding wound includes providing a molecular sieve
material in particle form and retaining the material in a mesh
structure, placing the mesh structure on a bleeding wound such that
the molecular sieve material comes into contact with blood flowing
from the wound, applying pressure to the mesh structure to ensure
contact of the material with the blood, and removing the mesh
structure from the wound.
[0013] An advantage of the present invention is that upon
completion of the application of any of the devices of the present
invention to a bleeding wound, the devices can be easily removed.
In particular, because the zeolite material is in granule, bead, or
pellet form and encased in a pouch or mesh structure, the material
can be cleanly pulled away from the treated wound and disposed of.
Accordingly, little or no irrigation of the wound is required to
flush away remaining zeolite. In devices in which the pouch
containing zeolite material is incorporated into an adhesive
bandage, the device can be left on the wound for the amount of time
necessary to cause clotting.
[0014] Another advantage is that the particlized form of the
zeolite material allows the material to react less exothermically
with blood. As the particle size increases (e.g., from fine to
coarse), the surface area of the particles that the blood can come
into contact with decreases. The porous nature of the material
still allows liquid blood constituents to be wicked away to cause
thickening of the blood, thereby facilitating the formation of
clots. Because the particle surface area exposed to the blood is
reduced, a less aggressive drawing of moisture from the blood is
realized, which thereby tempers the exothermic effects experienced
at the wound site.
[0015] Still another advantage of the present invention is that the
proper dose of molecular sieve material can be readily applied to
an open wound. Particularly when the device is a porous pouch
containing zeolite material, the device can be readily removed from
sterilized packaging and held directly at the points from which
blood emanates to facilitate clotting of the blood without spilling
powder or pellets outside the wound area. Guesswork, estimation, or
calculation of the amounts of molecular sieve material for
application to a bleeding wound is eliminated. Accordingly, little
or no molecular sieve material is wasted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic representation of a blood clotting
device of the present invention.
[0017] FIG. 2 is a side view of the blood clotting device of FIG. 1
illustrating the retaining of molecular sieve particles in a mesh
container.
[0018] FIG. 3 is a side view of a pressure pad incorporating the
molecular sieve particles encapsulated in a mesh container for
pressure application to a bleeding wound.
[0019] FIG. 4 is a perspective view of a bandage incorporating the
molecular sieve particles in a mesh container for application to a
bleeding wound.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Disclosed herein are devices and methods for delivering
materials to wounds to promote the clotting of blood and the
dressing of the wounds. The devices generally comprise expedients
or apparatuses that can be applied to bleeding wounds such that the
materials contact the tissue of the wound to minimize or stop a
flow of blood by absorbing at least portions of the liquid phases
of the blood, thereby promoting clotting. One apparatus comprises a
receptacle for retaining molecular sieve material in particulate
form therein. At least a portion of the receptacle is defined by a
mesh having openings therein, and at least a portion of the
particulate molecular sieve material is in direct contact with
blood through the openings.
[0021] The molecular sieve material used in the present invention
may be a synthetic polymer gel, cellulosic material, porous silica
gel, porous glass, alumina, hydroxyapatite, calcium silicate,
zirconia, zeolite, or the like. Exemplary synthetic polymers
include, but are not limited to, stylene-divinylbenzene copolymer,
cross-linked polyvinyl alcohol, cross-linked polyacrylate,
cross-linked vinyl ether-maleic anhydride copolymer, cross-linked
stylene-maleic anhydride copolymer or cross-linked polyamide, and
combinations thereof.
[0022] The molecular sieve material is preferably a zeolite. Other
molecular sieve materials that may be used include, but are not
limited to, faujasite. As used herein, the term "zeolite" refers to
a crystalline form of aluminosilicate having the ability to be
dehydrated without experiencing significant changes in the
crystalline structure. The zeolite may include one or more ionic
species such as, for example, calcium and sodium moieties.
Typically, the zeolite is a friable material that is about 90% by
weight calcium and about 10% by weight sodium. The calcium portion
contains crystals that are about 5 angstroms in size, and the
sodium portion contains crystals that are about 4 angstroms in
size. The preferred molecular structure of the zeolite is an
"A-type" crystal, namely, one having a cubic crystalline structure
that defines round or substantially round openings.
[0023] The zeolite may be mixed with or otherwise used in
conjunction with other materials having the ability to be
dehydrated without significant changes in crystalline structure.
Such materials include, but are not limited to, magnesium sulfate,
sodium metaphosphate, calcium chloride, dextrin, a polysaccharide,
combinations of the foregoing materials, and hydrates of the
foregoing materials.
[0024] Zeolites for use in the disclosed applications may be
naturally occurring or synthetically produced. Numerous varieties
of naturally occurring zeolites are found as deposits in
sedimentary environments as well as in other places. Naturally
occurring zeolites that may be applicable to the compositions
described herein include, but are not limited to, analcite,
chabazite, heulandite, natrolite, stilbite, and thomosonite.
Synthetically produced zeolites that may also find use in the
compositions and methods described herein are generally produced by
processes in which rare earth oxides are substituted by silicates,
alumina, or alumina in combination with alkali or alkaline earth
metal oxides.
[0025] Various materials may be mixed with, associated with, or
incorporated into the zeolites to maintain an antiseptic
environment at the wound site or to provide functions that are
supplemental to the clotting functions of the zeolites. Exemplary
materials that can be used include, but are not limited to,
pharmaceutically-active compositions such as antibiotics,
antifungal agents, antimicrobial agents, anti-inflammatory agents,
analgesics (e.g., cimetidine, chloropheniramine maleate,
diphenhydramine hydrochloride, and promethazine hydrochloride),
bacteriostatics, compounds containing silver ions, and the like.
Other materials that can be incorporated to provide additional
hemostatic functions include ascorbic acid, tranexamic acid, rutin,
and thrombin. Botanical agents having desirable effects on the
wound site may also be added.
[0026] In one embodiment of the present invention, a device for
facilitating the clotting of blood directly at a wound site is
shown with reference to FIG. 1. The device is a permeable pouch
that allows liquid to enter to contact blood clotting zeolite (or
other molecular sieve) material retained therein. Sealed packaging
(not shown) provides a sterile environment for storing the device
until it can be used. The device, which is shown generally at 10
and is hereinafter referred to as "pouch 10," comprises a screen or
mesh 12 and zeolite particles 14 retained therein by the screen or
mesh. The mesh 12 is closed on all sides and defines openings that
are capable of retaining the zeolite particles 14 therein while
allowing liquid to flow through. As illustrated, the mesh 12 is
shown as being flattened out, and only a few zeolite particles 14
are shown.
[0027] The zeolite particles 14 are substantially spherical or
irregular in shape (e.g., balls, beads, pellets, or the like) and
about 0.2 millimeters (mm) to about 10 mm in diameter, preferably
about 1 mm to about 7 mm in diameter, and more preferably about 2
mm to about 5 mm in diameter. In any embodiment (balls, beads,
pellets, etc.), less particle surface area is available to be
contacted by blood as the particle size is increased. Therefore,
the rate of clotting can be controlled by varying the particle
size. Furthermore, the adsorption of moisture (which also has an
effect on the exothermic effects of the zeolite) can also be
controlled.
[0028] The mesh 12 is defined by interconnected strands, filaments,
or strips of material. The strands, filaments, or strips can be
interconnected in any one or a combination of manners including,
but not limited to, being woven into a gauze, intertwined,
integrally-formed, and the like. Preferably, the interconnection is
such that the mesh can flex while substantially maintaining the
dimensions of the openings defined thereby. The material from which
the strands, filaments or strips are fabricated may be a polymer
(e.g., nylon, polyethylene, polypropylene, polyester, or the like),
metal, fiberglass, or an organic substance (e.g., cotton, wool,
silk, or the like).
[0029] Referring now to FIG. 2, the openings defined by the mesh 12
are dimensioned to retain the zeolite particles 14 but to
accommodate the flow of blood therethrough. Because the mesh 12 may
be pulled tight around the zeolite particles 14, the particles may
extend through the openings by a distance d. If the zeolite
particles 14 extend through the openings, the particles are able to
directly contact tissue to which the pouch 10 is applied. Thus,
blood emanating from the tissue immediately contacts the zeolite
particles 14, and the water phase thereof is wicked into the
zeolite material, thereby facilitating the clotting of the blood.
However, it is not a requirement of the present invention that the
zeolite particles protrude through the mesh.
[0030] To apply the pouch 10 to a bleeding wound, the pouch is
removed from the packaging and placed on the bleeding wound. The
zeolite particles 14 in the mesh 12 contact the tissue of the wound
and/or the blood, and at least a portion of the liquid phase of the
blood is adsorbed by the zeolite material, thereby promoting the
clotting of the blood.
[0031] Another embodiment of the present invention is a pad which
is shown at 20 with reference to FIG. 3 and is hereinafter referred
to as "pad 20." The pad 20 comprises the mesh 12, zeolite (or other
molecular sieve) particles 14 retained therein by the mesh 12, and
a support 22 to which pressure may be applied in the application of
the pad 20 to a bleeding wound. The mesh 12, as above, has openings
that are capable of retaining the zeolite particles 14 therein
while allowing the flow of blood therethrough.
[0032] The mesh 12 is stitched, glued, clamped, or otherwise
mounted to the support 22. The support 22 comprises an undersurface
24 against which the zeolite particles 14 are held by the container
12 and a top surface 26. The undersurface 24 is impermeable to the
zeolite particles 14 (migration of the particles into the support
22 is prevented) and is further resistant to the absorption of
water or other fluids. The top surface 26 is capable of having a
pressure exerted thereon by a person applying the pad 20 to a
bleeding wound or by a weight supported on the top surface 26. The
entire support 22 is rigid or semi-rigid so as to allow the
application of pressure while minimizing discomfort to the
patient.
[0033] To apply the pad 20 to a bleeding wound, the pad 20 is
removed from its packaging and placed on the bleeding wound. As
with the pouch of the embodiment of FIGS. 1 and 2, the zeolite
particles 14 are either in direct contact with the tissue of the
wound or are in direct contact with the blood. Pressure may be
applied to the wound by pressing on the top surface 26 with a hand
or by placing a weight on the surface, thereby facilitating the
contact between the zeolite particles 14 and the wound and
promoting the adsorption of the liquid phase of the blood. The pad
20 (with or without a weight) may also be held onto the wound using
a strapping device such as a belt, an elastic device, hook-and-loop
material, combinations of the foregoing devices and materials, and
the like.
[0034] Referring now to FIG. 4, another embodiment of the present
invention is a bandage, shown at 50, which comprises zeolite
particles 14 (or some other molecular sieve material) retained in a
mesh 12 and mounted to a flexible substrate 52 that can be applied
to a wound (for example, using a pressure-sensitive adhesive to
adhere the bandage 50 to the skin of a wearer). The mesh 12 is
stitched, glued, or otherwise mounted to a substrate 52 to form the
bandage 50.
[0035] The substrate 52 is a plastic or a cloth member that is
conducive to being retained on the skin of an injured person or
animal on or proximate a bleeding wound. An adhesive 54 is disposed
on a surface of the substrate 52 that engages the skin of the
injured person or animal. Particularly if the substrate 52 is a
non-breathable plastic material, the substrate may include holes 56
to allow for the dissipation of moisture evaporating from the skin
surface.
[0036] In the preparation of zeolite material for the devices of
the present invention (i.e., formation of the material into
particle form), an initial level of hydration of the zeolite may be
controlled by the application of heat to the zeolite material
either before or after the material is formed into particles.
However, it has also surprisingly been found that as the particle
size of the zeolite is increased, the moisture content has less of
a correlative effect on any exothermia produced as the result of
mixing the particlized zeolite in blood. As such, formation of the
zeolite material into the zeolite particles (shown at 14 in FIGS.
1-4), may be by extrusion, milling, casting, or the like.
[0037] Although this invention has been shown and described with
respect to the detailed embodiments thereof, it will be understood
by those of skill in the art that various changes may be made and
equivalents may be substituted for elements thereof without
departing from the scope of the invention. In addition,
modifications may be made to adapt a particular situation or
material to the teachings of the invention without departing from
the essential scope thereof. Therefore, it is intended that the
invention not be limited to the particular embodiments disclosed in
the above detailed description, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *